Zetta Blog

Incremental Backup: 3 Disaster Scenarios to Prep For

by Zetta Staff

May 31, 2015

We’ve recently published a tech brief outlining four different types of backup methodologies and incremental backup best practices. Of the methods discussed – full backups, incremental backups, differential backups and reverse incremental backups – reverse incremental is clearly the best option for providing fast restores while minimizing the amount of space needed for storage, as well as the time and resources needed to perform the daily backups.

Reverse incremental backups ensure that you always have a full backup of the most recent data to restore from, but the daily incremental only consists of any blocks which have changed since the previous day. All the work necessary to commit those changed blocks with the previous full backup set is performed during the backup, not during the restore. Let’s take a look at three different disaster scenarios where reverse incremental backups come in handy:

Recovery from Virus Attacks

Malware of all types frequently requires restoration of files or even rolling back entire systems to an earlier safe point in time. Ideally, one would be able to preemptively guard against malware, but with the number of new malicious files discovered daily running somewhere between 82,000 and 390,000, not even the best defensive measures are going to catch everything.

One of the biggest threats to guard against recently has been ransomware where hackers encrypt the files on their victims’ computers and block access until a ransom is paid. The most famous ransomware, CryptoLocker, garnered more than $27 million for its operators over a two-month period, just counting the Bitcoin payments made into four accounts. But there are many different types of ransomware in the wild and who knows what attack sector will be used next.

The best defense against ransomware and similar attacks is to have an up-to-date and readily accessible backup. Then, if attackers do encrypt your main data stores, those can be wiped and restored from the backup. With Zetta restore points, it is easy to select a specific date from before the attack to pull the data from. Depending upon the retention policy, it is even possible to restore data from a specific date years in the past.

Accidental Deletions

One of the most common sources of help desk calls is accidentally deleted files, particularly when an end user accidentally deletes important emails out of their Exchange folders. If they can’t restore a file locally, they can from the Zetta backup. Administrators can recover a single mailbox rather than having to restore Exchange in its entirety, and that mailbox can be restored from the last recovery point just prior to the accidental file deletion. Further, the last thing you want to do is restore an old copy of the file that has been updated. Zetta makes the most recent version available for a rapid restore.

Hard Drive Failures

It’s hard to gather accurate reliability statistics on hard drives. Google did publish an interesting study on the frequency of failures on its own systems, however this data is now out of date. Once a hard drive starts to fail, there’s nothing you can do to prevent it, so you need a backup that can immediately take over.

Faster Restore with Reverse Incremental Backup

Zetta’s reverse incremental backups speed the task of restoring accidentally deleted files and data lost from a virus attack or disk failure. How? You only have to restore a single backup version rather than piecing together bits from the last full and all the subsequent differential and incremental backups. You don’t even have to wait for restoration to be complete. During the rebuild process, users can mount the backup as a drive and access the data from our servers.

Keep in mind the whole purpose of backing up is so that the data can be restored quickly when needed. And that is why Zetta focuses its effort and architecture on speed and performance.